Method of and means for producing white light or daylight



A. CHIERA 2,110,500

METHOD OF AND MEANS FOR PRODUCING WHITE LIGHT OR DAYLIGHT March 8, 1938.

Filed Nov. 25, 1936 INVENTOR atented Marl 8, 1938 METHOD OF AND MEANS FOR PRODUCING WHITE LIGHT OR DAYLIGHT Albert Chiera, Washington, D. 0.

Application November 23, 1936, Serial No. 112,432

5 Claims. (01. 240-11) The object of my invention is that otproducing so that particles of color. of various densities are a light equivalent to daylight, or, to put it more obtained, each of which blends together with its accurately, of converting artificial light, emitted neighbours. At B, he 0 s t e thinnest, from incandescent filament lamps, from arcs, ,or heavier at and heaviest W l entirely from other sources, into a light closely approachlaflkihg at 5 ing daylight- Fig. 2 shows a sectional view of the same piece In th light t tt b an l t lamp of glass A over which the color is unevenly disbujb, an excess amount of th orange and red rays tributed, thinnest at B','heavier at C, and heaviest exist in its chromatic spectrum. To convert such and entirely lacking t 0 a light into a closer approximation of daylight Fig. 3 shows the color lightly sprayed over the unifor blue filters are generally used so that surface of a piece of glassE, the color particles the excessive amount of these spectral colors is are smaller, b the Overlapping is clearly Seenabsorbe At F the color is the thinnest, at G heavier, at H By said method, if the uniform blue glass filter y e Wh le at E the color is mis in is not sufiiciently dense, so as to absorb a correct slmllarly at F13 4, showmg Sectional View Of 15 proportion of the red and orange rays, naturally; a P e Of glass E the c0101 i$ the h at the transmittedlight will not be white, but if a heav1er at G, and the heaviest at H, while lackdenser uniform blue glass filter is used, so that a mg at greater amount of these rays is absorbed, it does Needless to say that the designs greatly not follow thatbecause or this greater absorption, h -7 the 0910! particles to Show the various den- 20 the light transmitted will be whiten On the conslties Ohtamedtrary, it may begreenish-yellow or bluish, because In the actual 06955 of PP the Particles t o h of th d or orange rays have been of color are much more irregular in shape than b b d the design shows, and the variations of densities White light is really composed of red, yellow more numerous. 25

and blue, and, an equal proportion of these colors In the spraythe 60101 is Split up ihtO Very must be present before white light will result. D particles of 00101 which naturally assume Hence, to absorb a sufiicient amount of the red at more circular and regular Q and orange r y by a if bl filter and t Practically the same result obtained: by stipthe same time allow a suificient amount of these Phhg, can he had by p y the 00101 it a 3 rays to pass through, I f d ery um t do sprayer. The effect of the color scattered, shows becau f'the limitation of th t d used in fact small points, or larger dots, according to Therefore, I hit upon the idea of scattering the Whether the opening of t e nOZZle s Ve y Small blue color in the filter so that a general absorption or large The p r i l overl pp n of p ti e of t red d orange rays ld t, b t t of color, or liquid color flying in small drops, will 35 the same time. permitting these rays to pa produce a gradation of shades, just as it appears through said filter from those points of it, where in a ipple- In b h cases there m y be m the color is applied very thinly,'or where it is points on he u f c of n l r mp bulb entirely lacking. in which the color may be lacking, but these 49 The glass surface of an electric lamp bulb is p ints re few and infinite imal. 40 the base or foundation over which a blue coloring The main difference between the two methods agent is scattered by stippling or by proper lies in the fact that by scattering the color with spraying. a sprayer, its distribution is more mechanically This coloring medium consists of amineral blue perfect and finer, but in this latter case, the 40 color mixed together with a sultablevehicle such color must be thinly applied to conserve the efas silicate of soda or potassium. fect of light and dark dots, which would be de- By the word stippling I means that a coat or stroyed if a dense coat would be sprayed. fiat color is applied over a surface, and while it is From the definition given above it is evident still wet, it is broken up by an up and down movethat the surface efiect of the blue color produced merit of the brush, so that the individual bristles by stippling or by proper spraying will differ or hairs of the brush will cause the color to be scatfrom the effect of the same blue color when unitered into' small points or dots of color which tend formly and evenly distributed over a surface; for to run together. i example, in a sheet of blue glass, in which the For example, Fig. 1 shows the coloring agent color is an integral part of the glass itself, or in stippled over the surface of a piece of glass A, a blue bulb blown from liquid blue glass and 55 resulting from the two methods: by the latter the light is uniformly intercepted and absorbed by a single shade of blue, whereas, by the former, it is intercepted and absorbed by several shades obtained by the stipple. Similarly the same difference exists when the color is applied by spraying. I

The several gradations of blue obtained by the stipple will cause the yellow-orange color of the illuminant to be absorbed in proportion to the various shades or densities present, so that different color rays will combine to produce a light equivalent to daylight. I

Having given a full description of both the method and principle of this invention, I do not wish to limit it as applicable to incandescent electrical bulbs only, since identical effects could be obtained by using the same process on glass of whatever shape and size, surrounding an incandescent bulb or by using said process on a fiat or convex plate of glass, in connection with an opaque or semi-opaque reflector.

Moreover, -I found that the glass, whether pertaining to filament electric bulbs, globes, glass shades or fiat or convex glass, need not necessarily be colorless, but they may be of a light blue or of 'a greenish-blue tone, in which case it wouid be best that the stippling blue color verge slightly toward the violet or have a suggestion of a violetbluish tone.

For this reason I wish to vary the tone or quality of the blue-used in the medium to suit any particular quality of light emanated from an incandescent clear bulb, or from a bulb, having a blue color, or from an arc or other illuminants, in order to produce a light equivalent to daylight in accordance with the principies of my invenion;

Thus, it will be understood that nothing contained in the foregoing description is to be implied or construed as restricting the scope of the protection, hereby secured, in respect to a definite tone of blue used, of its quality of color or quantity thereof, or to the external form or other quality of design of lamps, globes or shades, or to the shape and size of the incandescent bulbs orl'to the entire or partial surface over which said medium is to be stippled or unevenly distributed'by whatever method used.

The color or tone of the blue shall be limited within the Fraunhofer lines F and G of the nor- :nal solar spectrum.

together with its neighbours.

3. A light corrective filter, consisting of a heat resisting coloring agent, sprayed over the outside or inside of an electric lamp bulb, so as to obtain particles of color of various densities, each of which blends together with its neighbours.

4. A light filter consisting of a heat resisting coloring agent stippled or sprayed over the surface of a light transmitting member so as toobtain particles of color of various densities, said filter being adapted for use with an artificial light source. v

5. A light corrective filter consisting of a heat resisting blue coloring agent, sprayed or stippled over the surface of a blue electric lamp bulb, so

ALBERT CHIERA. 

